George j



(No Model.)

GLJ. HOTGHKISS. TRAP DOOR FOR USE IN MINES.

Patented Apr. 9, 189 5.

* :NITED STATES PATENT OFFICE.

GEORGE J. HOTOHKISS, OF EVANSVILLE, INDIANA, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO LOUIS A. SCHULTZ AND THE GROTE MAN- UFACTURING COMPANY, OF SAME PLACE.

TRAP-DOOR FOR USE IN MINES.

SPECIFICATION forming part of Letters Patent No. 537,418, dated. April 9, 1895.

Application filcdMay 5, 1894- Serial No; 510,210. (No model.)

To all whom it may concern:

Be it known that I, GEORGE J. HOTOHKISS, a citizen of the United States, residing at Evansville, in the county of Vanderburg, State of 5 Indiana, have invented certain new and usef ul Improvements in Trap-Doors for Mines, of which the following is a specification.

Myinvention relates to an improvement in an apparatus for opening and closing doors to and gates over and upon car-tracks, but more particularly trap-doors in mines, by the action of the cars running on the track, the object of which is to construct a door that is automatically opened and closed by the action of I 5 the cars running on the track, and to provide a trap-door for use in mines that will always be opened and closed at the proper time for the passage of the cars, thereby making the ventilation throughout the mine more perfect.

I attain these objects by the device illustrated in the accompanying drawings, in which- Figure 1., is a plan of the apparatus, showing it as attached to the car-track and the door. Fig. 2., is a plan of the semi-circular piece, which gives motion to the door. Fig. 3., is a section of the vertical shaft, showing that part around which the chainsrun when the shaft rotates and also shows the position and location of the chains. Fig. 4., is a side View of the trip-lever. Fig. 5., is a side view of the swivel lin'k, showing the position and location of the coil springs, the central bar, the two links, and the two short bars threaded at one end and having a ring on the opposite 3 5 end.

A., is the trap-door.

13., is the frame supporting the door, which is made in three or more pieces.

6., is the track on which the rollers Y. Y.,

40 run, and the said track is securely fastened to one side of the top part of the frame.

D., is the car track, upon which the cars run, and over and upon which the door frame B., is constructed, and the door A., swings.

E., is the vertical shaft, the length of which is equal to the height of the door A., and is pivotally connected to the car track at the lower end, and its top end is pivotally connected to the brace X., which brace X., is connected to, and projects outwardly at right angles from the top of the door frame B. This vertical shaft is placed at a distance from the door A., equal to one half of the length of the straight edge of a thin, flat, semi-circular piece F., which is placed at right angles to the door A., near its top end so that the semi-circular edge fits against the door. The semi-circular piece F., has a single groove T., in its semicircular edge in which the cables W. run. The length of the cables W. W., is a little more than the width of the door. One end of each cable W., is fastened to the door A., at a height equal to the height of the semi-circular piece F., and the opposite end of the cable is then connected to one end of the semi-circular piece F., farthest from the point at which it is connected to the door A. Near the lower end of the vertical shaft E., is a drum G., around which the chains H. H., run.

I. I., are cables connected to the chains H. H., which pass around the drum G., and also to the chains H. H., which pass around the grooved wheels J. J. The grooved wheels J. J are journaled horizontally, each at a distance from the vertical shaft equal to the combined length of the chains and the cables.

In Fig. 4., K., is the trip-lever, which projects slightly over the car rail at right angles to the track and is moved by the force of the car running against it. A trip lever is located between each of the grooved wheels J. J., and the vertical shaft E.

The trip-lever K., has a coil spring 5., which holds it in position at right angles to the car track and is composed of two short bars b. 1)., connected at the rear end to a straight bar on, which is pivotally connected at its bottom end to the car track D., and at its top end to the bow L. On the opposite end of the two straight bars 6. b., is a square piece Z., against which the car strikes. Between and near the middle of the bars b. 1)., is securely fastened a piece 0 having a circular aperture R, in its middle, through which circular aperture R, runs the central or middle bar in the swivel link M.

In Fig. 5., a side view of the swivel link M., is shown. The swivel link consists of a straight bar M., threaded at each end; two coil springs P. P., two links N. N., two short bars 0.0., threaded at one end, having a ring on the opposite end in which the cable T., is tied.

The object of the swivel link, as a whole, is to provide a means by which the trip-lever can pull the cable and. by which the cable can be tightened by screwing up the two links N. N., in such a manner as to draw the two short bars 0. 0., and the central bar M., closer together. The coil springs P. P., prevent the trip lever from striking against the links N. N., and break the force of the blow received by the trip lever when brought in contact with moving cars.

This door may be made of any material and any size desired. It is opened and closed by the action of the cars running on the car track, in this manner. The cars approach the door and strike the trip-lever K., which; pulls the cable 1., thereby turning the vertical shaft E., and the semi-circular piece E, which semi-circular piece pulls the cable W., that is attached to its end which is against the door when shut, thus opening the door by sliding it back from over the car track. The cars pass through the door and strike the opposite trip-lever K., whichv pulls the cable I.,

reversing the motion of the vertical shaft E.,

and semi-circular piece F., thereby closing the door in the same manner as it is opened, as above described. The distance between each of the trip-levers K. K., and the door A., must be greater than the length of the train of cars passing through thedoor, as the hindmost car must pass entirely through the door before the front car reaches the trip lever.

The object in using chains to run around the drum G., and the grooved wheels J. J., is to prevent wear and strain on the cables.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In an apparatus for opening and closing trap doors in mines, the combination of the trip levers K. K., the grooved wheels J. J., the vertical shaft E., the semi-circular piece F., the cables I. I., and W. all connected to each other, and to the door, as above de scribed, and used for the purposes hereinbefore set forth.

2. In a trap door for use in mines, and an apparatus for opening the same by the motion of the cars running on the track, the combination of the door A., the frame 13., the track 0., attached to the upper part of the door frame, the vertical shaft E., having a drum G., thev semi-circular piece F., having a groove T., in its semi-circumferential edge, the connected chains H. H., and H. I-I., the cables I. I., the grooved wheels J. J., the trip lever K., the swivel link M., the cables WV. vV., connecting the door A., and the semi-circular piece F., the rollers Y. Y., attached to the top of the door A., and running on the track 0., all

fmade, constructed and connected, and used for the purposes heretofore specified.

GEORGE J. HOTGHKISS. \Vitnesses:

LOUIS O. RASCH, A. J. MoCUToHAN. 

